Wrench



1966 A. L. VON TERSCH 3,269,226

WRENCH Filed Dec. 4, 1963 flTTOR/VEY United States Patent G 3,269,226WRENCH Alfred L. von Tersch, Waterloo, Iowa, assignor to LisleCorporation, Clarinda, Iowa, a corporation of Iowa Filed Dec. 4, 1963,Ser. No. 328,015 3 Claims. (Cl. 81-64) This invention relates to awrench, and specifically to a type of wrench employing a spiral springfor encircling and grasping the body of a cylindrical element.

This invention proposes the provision of a wrench capable of rotatablyencircling an element to be removed, whereby rotation of the wrench inone direction increases its grip on the element, and rotation in theopposite direction decreases the grip. The wrench is constructed of aspirally-wound spring and a torque receiving and transmitting memberattached directly to the spring on an arcuate portion of one of aplurality of turns comprising the spring, with the remainder of theturns being completely free to expand and contract at will, and toencircle the element for removal thereof.

The element to be removed by the wrench of the present invention is aconventional automotive oil filter, commonly called a spin-on filter. itis so called because all that is required to install the filter is tothreadably engage a tapped opening formed on the longitudinal axis ofthe filter with an externally threaded stub shaft on a vehicle engineblock. As the threading or rotating is readily accomplished, the filtercan actually be caused to spin during the threading operation without agreat deal of effort on the part of the mechanic.

Difficulty can ensue, however, with regard to removal of the filter,should the mechanic use an excessive amount of torque during the spin-onoperation. Over a period of use, the threaded engagement can becomesufficiently locked-so to speakthat reverse threading of the filter cannot be accomplished by a normal application of torque thereto. Thedifficulty is enhanced due to the necessary provision on the filter ofan O-ring which is compressed against the engine block as a result ofinstallation of the filter. Due to the exposure of the ring to heat fromthe block and to heated oil, quite often the ring will swell, thuscompounding the locked nature of the filter relative to the engineblock.

When the filter is so locked, several makeshift means of removing thefilter. are resorted to by mechanics. Quite often a strap wrench will beused, but this use fails due to the surface of the filter being slick,having an oily film thereon. A mechanic might also punch a hole in thefilter so as to force a bar therethrough to obtain leverage to rotatethe filter. This latter method is quite unsatisfactory for severalreasons. First, oil may spill from the filter thus making the operationrather messy. Secondly, the necessary room about the filter foraccesibility of the bar may not be be provided.

It is therefore an object of this invention to provide an improvedwrench.

It is also an object of this invention to provide an improved wrench forrotatably removing a cylindrical element which has been rotatablyengaged with an object.

It is another object of this invention to provide a wrench whichencircles the element it is to rotate, and which wrench either increasesor decreases its grip thereon depending upon its direction of rotation.

It is another object of this invention to provide a spiral spring torquewrench where the torque is applied to the spring at one end thereof ondiametrically opposite points of a single turn, and further wherein astructure connected to the spring initially receives the applied torqueon the longitudinal axis thereof.

It is an object of this invention to provide a wrench capable ofaccomplishing the above designated objectives which is easily andeconomically manufactured, rugged in structure enabling repeated usethereof, and elfective in operation.

These objects, and other features and advantages of this invention willbecome readily apparent upon reference to the following description,when taken in consideration with the accompanying drawings, wherein:

FIG. 1 is a perspective view of the wrench of this invention inassembled relationship with an automotive oil filter;

FIG. 2 is a side elevational view of the wrench of FIG. 1;

FIG. 3 is an end elevational view of the wrench, as viewed from the leftend of FIG. 2;

FIG. 4 is a cross-sectional view taken along the line 44 of FIG. 3; and

FIG. 5 is a cross-sectional view taken along the line 5-5 in FIG. 3.

Referring now to the drawings, a preferred embodiment of the wrench ofthis invention is indicated generally at 10 in FIG. 1 and is shown inassembled relation with a conventional oil filter 11 which has beenthreaded onto the externally threaded stub shaft 12 protruding throughan opening (not' shown) in a vehicle engine block 13.

The filter 11 includes a circular, dome-shaped housing 14 whichencompases a filter screen 16, and which is closed at the bottom by aplate 17 having a plurality of arcuately spaced openings 18.Encompassing the openings 18 is an O-ring 19 which is bonded to thebottom of the plate 17. The plate is threaded internally at a thickenedcentral portion 15 thereof for threading onto the stub shaft 12.

As discussed previously, due to a number of factors, at times the platethreads lock to the stub shaft 12 and the O-ring 19 sticks to the engineblock 13 to an extent that an attempted manual turning of the filter 11to thread it off the stub shaft can not be accomplished.

To overcome the locked nature of the filter 11, the wrench 10 isconstructed so as to grip the surface of the filter housing 14 by meansof a plurality of flat, steel bands as now described. The wrench 10comprises in general a torque receiving element indicated generally at20 in FIG. 2, and a member 21 connected to the torque receiving elementadapted to completely encircle and grasp the filter housing 14 (FIG. 1).Upon receipt of torque by the element 20, the member 21 clamps thefilter housing 14 with a pressure equally distributed over the fullsurface of the housing 14.

Specifically, the torque receiving element 20 includes an elongatedU-shaped bar 22 having a flat central portion 23 (FIG. 4), a pair offlat side portions 24 extended oppositely each other downwardly andoutwardly from the central portion 23 at equal angles, and a pair offiat ends 26 extended parallel each other and in planes at right anglesto the plane of the central portion 23. As best illustrated in FIGS. 3and 5, a pair of arms 27 extend in opposite directions from thelongitudinal center of the bar 22 and at right angles to the main axisthereof. It will be noted (see FIG. 3) that the overall length of thearms 27 is less than the overall length of the central and side portions23 and 24, respectively.

Secured to the bar 22 is a torque receiving hexagonal nut 28, a stem 29of which is stationan'ly secured Within a base 31 provided at thelonigtudinal center of the bar 21. In the specific embodiment of thewrench 10, the nut 28 may be rotated by any type of three-quarter inchwrench.

The member 21 comprises a spiral spring of spring steel having aplurality, approximately four, of turns 32, all of which are flat. Aslight frustrum is provided by each turn, 32a for example, nearest thebar 22 being slightly larger in diameter than the next succeeding turn32. The end 33 of turn 32a is affixed by a pair of rivets 34 to theinner surface of one end 26, whereas a part of the turn 32adiametrically opposite the end 33 is also affixed by rivets 36 to theinner surface of the opposite end 26. The end 37 of the last turn 32b isturned inwardly toward the center of the spring member 21 as best seenin FIG. 3.

By referring specifically to FIGS. 2 and 3, it will be seen that the nut28 is not only located at the longitudinal center of the bar 22, but itis also located on the longitudinal center of the spring member 21.Thus, torque is applied to the nut 28 and received by the bar 22 on thelongitudinal center of the spiral spring 21. The torque applied to thetorque receiving element 20 is then transmitted to the spring 21 tooperate the wrench 10 in the following manner.

To install the wrench 10, the outer turn 32a at the open end thereof isplaced over the outer end of the filter 10 and the wrench 10 is rotatedin a clockwise direction as viewed in FIG. 1. This results in the springpart of the wrench 10 walking onto the filter 11 as the turns 32 tend toenlarge in diameter. The rotation is continued until the wrenchcompletely encircles the filter to the fullest extent.

A wrench is then applied to the head nut 28, the wrench being ofwhatever type is permitted by the space available. The nut 28 is thenrotated in a counter-clockwise direction. In response to this reversedrotation, the turns 32 tend to contract, resulting in their applying apressure to the filter housing 14 over substantially its entire lengthand circumferentially a plurailty of times depending on the number ofturns 32.

Continued counter-clockwise rotation of the nut 28 transmits increasedtorque through the element 20 to the spring 21. It has been found thatthe provision of the arms 27, as illustrated prevents the bar 22 fromabsorbing undue tensional stresses and aids in transmitting a balancedand stabilized torque to the spring 21. This increased torque results inbreaking the bond of the plate-to-stub shaft and/ or the O-ring 19 withthe engine block 13. The filter 11 is then completely rotated off thestub shaft 12. The wrench 10 can then be removed from the filter 11 bywalking it off backwardsso to speak.

It can readily be appreciated that the installation of the wrench 10 andthe removal of the filter 11 thereby are accomplished with ease andeffectiveness which obviates punching holes in the filter and othermessy and generally unsatisfactory makeshift filter removal devices.

Although a preferred embodiment has been described herein, it is to beremembered that various modifications threadably attached to an objectcomprising in combina tion:

an elongated bar U-shaped inside elevation and having a pair ofprojections extended in opposite directions from the longitudinal centerthereof, said bar adapted to receive torque; and

a resilient spiral member, said bar connected at opposite ends thereofto diametrically opposed parts of one end of said member.

2. A wrench for rotatably removing a circular element threadablyattached to an object comprising in combination:

an elongated bar U-shaped in side elevation and having a pair ofprojections extended in opposite directions from the longitudinal centerthereof;

a resilient spiral member, said bar connected at opposite ends thereofto diametrically opposed parts of one end of said member; and

a device secured to said bar at the longitudinal center thereof forreceiving torque and for transmitting said torque to said bar.

3. A wrench for rotatably removing a circular element threadablyattached to an object comprising in combination:

an elongated bar U-shaped in side elevation and having a pair ofprojections extended in opposite directions from the longitudinal centerthereof;

a spiral spring, said bar connected at opposite ends thereof todiametrically opposed parts of one turn of said spring at one endthereof; and

a torque receiving and transmitting device secured to said bar at thelongitudinal center thereof on the longitudinal center of said spring.

References Cited by the Examiner UNITED STATES PATENTS 2,664,021 12/1953Clayson 81-64 2,805,590 9/1957 Nelson 81-64 X 2,820,383 1/1958 Red 81642,959,994 11/1960 Kile 81--64 WILLIAM FELDMAN, Primary Examiner.

JAMES L. JONES, JR., Examiner.

1. A WRENCH FOR ROTATABLY REMOVING A CIRCULAR ELEMENT THREADEDLYATTACHED TO AN OBJECT COMPRISING IN COMBINATION: AN ELONGATED BARU-SHAPED IN SIDE ELEVATION AND HAVING A PAIR OF PROJECTIONS EXTENDED INOPPOSITE DIRECTIONS FROM THE LONGITUDINAL CENTER THEREOF, SAID BARADAPTED TO RECEIVE TORQUE; AND A RESILIENT SPIRAL MEMBER, SAID BARCONNECTED AT OPPOSITE ENDS THEREOF TO DIAMETRICALLY OPPOSED PARTS OF ONEEND OF SAID MEMBER.